New battery-cooling technology means EV charging in under four minutes for student racing team

The team aims to reduce the charging time for electric cars, which it feels vital to make electric driving easier, and therefore more accessible for consumers.

"InMotion has taken up that challenge and is now truly getting close to a pit-stop-worthy charging time," said the team.

Cell-level cooling technology

A substantial amount of heat is created during fast charging, resulting in an accelerated deterioration of battery cells.

Previously the team had created a new module-level cooling system in which cooling plates filled with coolant were put between the modules holding the cells. This allowed it to extract a significant amount of heat from the pack.

However, the team soon realized that to drain heat from the battery pack as effectively as possible, you needed to cool it as near to the battery cells as possible.

Therefore the team developed a method to enable cooling at cell level, with coolant flowing between each cell. "This means we can extract even more heat from the pack. It has a tremendously positive effect on the lifespan and repeated fast charging. A 24-hour test shows minimal degradation of the battery pack as a result", explains team manager Julia Niemeijer.

Since cell-level cooling technology is not commonly used in the EV industry, the team had to develop the technology itself.

According to Niemeijer, the space between cells in the module only measures a few millimeters and it was challenging to implement the cooling technology. "This required us to be extremely precise in our work. We are thrilled that we have found a method that makes this possible."

Highly customizable

The technology can be scaled up to produce batteries of different sizes with similar charging times.

Stijn van de Werken, Technical Manager at InMotion said: "There is often a misconception that smaller battery packs charge faster than larger ones. However, this is not the case. No matter how large you make the pack, the charging time will remain the same as long as the charging station can supply sufficient energy."

This opens up a plethora of implementation options in the fast-growing EV and battery landscape.

The technology was applied by the student team in an LMP3 racing vehicle. The LMP3 is the prototype class of the legendary 24 Hours of Le Mans, created to allow novice drivers and new teams to compete.

InMotion hopes to demonstrate the technology at the 24 Hours of Le Mans, where the battery pack will be tested under the most extreme circumstances, especially long-distance racing.